Variac mode question

[mixsit]

Does it reduce voltage to the entire amp, of just certain sections or circuits?
The manual has a fairly straight forward statement about it which leads me to think it may indeed mean everything sees lower voltage, just wondering.
Thanks

 

[bandit2013]

Variac mode feeds power to the PT on a different tap of the primary side, thus it will affect everything on the secondary side of the power transformer. However most of the accessory circuits for the switching logic control and the sensitive preamp tube heater circuits that are DC will remain consistent as they are regulated so there is plenty of headroom on those circuits to maintain consistent operation at full power or variac power.

 

[mixsit]

Thank you Sir! 'Question came up for my mind when someone on a form asked about the use of variacs. I played with one on a Twin for a bit but that was years ago.